Design Patterns in ActionScript-Final Note

In this series, we talk about the 23 design patterns. We use some examples to illustrate how and when to use the patterns, but there is still something I’ve to say here.

Why design patterns?

In my view, design pattern is just a solution to some types of problems, and just a general solution. We use this pattern is just because this pattern is proved to be useful or efficiency to this kind of problem. In general, it’s a better solution, maybe not the best one, but it’s enough in most cases.

With these patterns, you can communicate with your colleagues more easily during the development. You just need to say the pattern name, such as “Singleton”, and your colleagues will understand, “Oh, it’s a singleton, I can’t use the new operator.” You don’t need to explain to your colleagues what the pattern it is.

How and when to use the patterns?

It depends on your experience and what the problem is. Understanding the problem is the first step and the most important step when you build an application.

The following is the conclusion from the GoF book, maybe it helps you.

Abstract Factory

Provide an interface for creating families of related or dependent objects without specifying their concrete classes.

Avoid coupling the sender of a request to its receiver by giving more than one object a chance to handle the request. Chain the receiving objects and pass the request along the chain until an object handles it.

Define an object that encapsulates how a set of objects interact. Mediator promotes loose coupling by keeping objects from referring to each other explicitly, and it lets you vary their interaction independently.

Define the skeleton of an algorithm in an operation, deferring some steps to subclasses. Template Method lets subclasses redefine certain steps of an algorithm without changing the algorithm’s structure.